An advantage that the LSES gains from crossing a variety of disciplinary boundaries is that it is in a position to apply techniques and concepts developed in one area of research to another area where their usefulness may not yet be recognized. One situation where such cross-disciplinary transfer of methodology seems particularly appropriate is the use of structural equation modeling (SEM) for the measurement of neurobiological processes and for modeling the causal relationships among them. The LSES is in close contact with the statisticians who are continuing the development of this complex statistical methodology and expanding its application to different types of data. At present we are applying SEM techniques to four areas of neurobiological, neuropsychological cognitive research-- 1) eye tracking behavior 2) neurological soft signs 3) PET data relevant to the hypothesized corticostriatal-thalamocortical loops 4) the structure of memory in normal and brain damaged individuals.